Sliding valve

Abstract

A sliding valve having a valve slider that can be axially displaced relative to the valve sleeve in order to determine the size of variable passage cross-sections and for establishing a pressurization connection between a high-pressure connection and a working connection and a pressure-reducing connection between the working connection and a low-pressure connection, in that control edges running in the circumferential direction are configured on the outer circumference of the valve slider, which interact with the control edges of the valve sleeve. The control edges of the valve sleeve are configured as edges extending in the circumferential direction relative to the symmetry axis, which are a component of a lateral face of the valve sleeve.

1. A sliding valve, arranged in a housing, in which hydraulic connections (A, T, P) are formed, for regulating a hydraulic pressure at a working connection (A) to values between a pressure at a low-pressure connection (T) and a pressure at a high-pressure connection (P), comprising:
 a valve sleeve, a main bore of which defines an axis of symmetry (S) and a surface area, 
 a rotationally symmetrical valve slide which is received so as to be axially movable in the main bore and a displacement position of which is influenced by a valve activation force (F) acting upon the valve slide and also by a pressure force acting upon an end face of the valve slide and exerted by the pressure in the working connection and by a force of a restoring spring, 
 wherein the position of the valve slide in a direction of the axis of symmetry (S) in relation to the valve sleeve fixes a size of variable passage cross sections both of a pressure build-up connection between the high-pressure connection (P) and the working connection (A) and a size of a pressure breakdown connection between the working connection (A) and the low-pressure connection (T), 
 wherein control edges are formed which extend peripherally in a circumferential direction on an outer circumference of the valve slide and which cooperate with control edges of the valve sleeve, 
 wherein the control edges of the valve sleeve extend peripherally in the circumferential direction with respect to the axis of symmetry (S) and which are an integral part of a surface area of the valve sleeve. 
 
     
     
       2. The sliding valve as claimed in  claim 1 , wherein the main bore of the valve sleeve is a through-bore, and the control edges are formed by issues of the main bore into the end faces of the valve sleeve. 
     
     
       3. The sliding valve as claimed in  claim 2 , wherein the end faces of the valve sleeve are planar faces that are oriented perpendicular to the axis of symmetry (S). 
     
     
       4. The sliding valve as claimed in  claim 1 , wherein a peripheral groove in the valve slide, together with the surface area of the valve sleeve, forms a hydraulic annular chamber which is connected permanently to the high-pressure connection (P) via a radial bore in the valve. 
     
     
       5. The sliding valve as claimed in  claim 4 , wherein a peripheral groove in the valve slide, together with the surface area of the valve sleeve, forms a hydraulic annular chamber which is connected permanently to the working connection (A) via a radial bore in the valve slide. 
     
     
       6. The sliding valve as claimed  claim 5 , wherein a groove is formed in a web, extending peripherally with respect to the axis of symmetry (S), of the valve slide between the two annular chambers and receives an elastomeric sealing ring for hydraulic separation of the annular chambers. 
     
     
       7. The sliding valve as claimed in  claim 5 , wherein the valve slide has within the annular chambers a plurality of radial projections which, for a purpose of guiding the valve slide radially within the main bore of the valve sleeve, project as far as the surface area of the valve sleeve, the projections beings spaced apart in the circumferential direction from one another and in the axial direction from the peripheral webs delimiting the annular chambers, in such a way that a hydraulic through-flow is not impaired. 
     
     
       8. The sliding valve as claimed in  claim 1 , wherein the valve activation force (F) is transmitted to the valve slide via a mechanical contact force, at least one surface of two bodies touching one another for force transmission. 
     
     
       9. The sliding valve as claimed in  claim 1 , wherein the valve slide and the valve sleeve are introduced as a preassembled structural unit into a stepped bore which is located in the housing and which is closed on a working-pressure side by a cover fixed to the housing. 
     
     
       10. The sliding valve as claimed in  claim 9 , wherein the restoring spring is a compression spring that is supported on the cover fixed to the housing and on the valve slide. 
     
     
       11. The sliding valve as claimed in  claim 9 , wherein a stop for limiting a travel distance of the valve slide is formed in the cover fixed to the housing. 
     
     
       12. The sliding valve as claimed in  claim 11 , wherein to maintain a hydraulic flow in a stop position of the valve slide, the valve slide is provided with at least one transverse bore or with a radial fluid passage aperture that is equivalent to a transverse bore.